Three-dimensional (3D) form is a fundamental perceptual category that transcends individual sensory systems. A vivid percept of 3D form can be obtained from touch, from vision, or from both. The neural representations that underlie 3D for perception may be supramodal (independent or the individual sensory systems), multimodal (based on strong links between representations in the individual systems, or a mixture of the two. There are two compelling reasons to undertake the study of 3D form perception. The first is that 3D form perception is a paradigm of sensory integration in the brain. The second is that 3D form perception is a fundamental cognitive function whose neural mechanisms are almost completely unknown. Four individual projects are proposed, two involving somatosensory neurophysiology and two involving visual neurophysiology. Tactual perception of 3D form simultaneously on the conformation on the hand and on the integration of information from the multiple points of contact with the fingertips. Project 1 (Johnson) deals with how neurons respond to 3D stimuli (edges, corners, curvature) at multiple points of contact. Project 3 (Hsiao) concentrates on how responses depend on the conformation of the hand. Visual perception of 3D form is derived from 2D images; this process depends on the integration of visual information with implicit knowledge about optics and the 3D world. Project 2 (Conner) addresses how neurons in visual cortex represent the basic elements of 3D share (3D edges, corners, surface curvature, and simple volumes like blocks and cylinders). Project 4 (von der Hyedt) concentrations on the integration of binocular and monocular and cue conflict. The core project concerns shared services, administration, and project coordination.